Theory And Algorithms For Information Hiding In Digital Image

The rapid enhancement of the computer technique and the widespread popularization of the communication technology are providing the broad space for the information hiding in research and application. The information hiding technique hides the secret information in the ordinary information (carrier information) in the process of transmission so as to guarantee the secret information not easily stolen or destructed. This dissertation details foundational knowledge of the technique and further analyzes the algorithms for information hiding in digital image, the main tasks are as follows:(1) The algorithms for image scramblingThe dissertation outlines the research situation of image scrambling, and then studies one algorithm based on matrix transformation and proposes one algorithm based on S box in AES. In order to confirm the validity of the algorithm, the performances of scrambling image are analyzed by the gray histogram, the expectation, the standard deviation, the correlation coefficient etc.(2) The algorithms for information hiding in digital image based on DCT The dissertation introduces DCT and its application for the information hiding indigital image. And three algorithms are proposed, one algorithm based on fuzzy entropy and auto-adapted quantification, one algorithm based on variation degree, one algorithm based on fuzzy entropy and image fuzzy. The experimental results show that the proposed algorithms are perceptually invisible and robust to some image processing such as loss JPEG compression, cropping, and noise.(3) The algorithm for information hiding in digital image based on DWT One kind of blind information hiding in digital image based on error correctingcoding and the DWT characters is proposed. Experimental results indicate the algorithm has a better transparency, robustness and usability.